Variable electric lamp



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STATES [Patented JOSEPH ARDO AND FRANK MELFO, 0F NEWHALL, WEST VIRGINIA.

VARIABLE ELECTRIC LAMP.-

.Application filed September 21,1921. Serial No. 502,279.

To all whom it may concern:

Be it known that we, JosErH ARno and Frank MELFO, citizens of the United States, residing at Newhall, in the county of Me- Dowell and State of West Virginia, have invented certain new and useful Improvements in Variable Electric Lamps, of which the following is a specification.

- This invention relates to incandescent electric lamps having reference to the mechanical features of construction and not to the composition of the filament.

The invention has for an object to provide an electric lamp with a novel arrangement of parts whereby the lamps may be dimmed or increased in brilliancy as may be 7 desired.

A further object is' to provide a lamp permitting of ready renewal of the filament if broken, or of the globe, or of both, as may be desirable or necessar For furthercomprehension of the invention, and of the objects and advantages thereof, reference will be had to the.followmg description and accompanying drawings, and to the appended claim in which the various novel features of the invention are 'more particularly set forth. Figure l of the drawings is a side View, with parts broken out into vertical section, of an incandescent electric lamp constructed according to the invention.

Figure 2 is a horizontal section on the line 22 of Figure 1; I

Figure 3 is a diagram of the Wiring circuits.

In constructing our improved lamp we provide a plug element having a threaded portion 10 of ordinary shape and size which is adapted to be screwed into any ordinary socket. This plug member is extended in cylindrical form on its lower endbeyond the screw threads as at 11, providing an intenor chamber 12 in which the light control elements are contained. At its base the plug member is extended radially outwardly in the form of a flat disk 13 having spaced cylindrical flanges 14 and 14! adjacent its edge, this dish forming a cap or cover for the lass bulb or globe.

ithin the lower end ,of the cylindrical part 11 is set a circular block 15 of insulating material whichmay be fixed in place in any suitable manner, being axially localized by engagement with an interned head 16 on the element 11. This block 15 serves to support the filament and also has mounted thereon the fixed contact members of the light control device.

The filament 18 may be of ordinary construction and wound back and forth over star-shaped upper and lower supports in the usual manner, the lower supports being in the form of wires 19 projected radially from an insulating disk 20 fixed to the bottom of a rod 21 depending'fromthe block 15. The upper supports are likewise in the form of wires 23 preferably of copper, or other suitable material which radiate from the bottom of the block 15 and are carried upward through the latter to connect to contact studs '24 mounted on the tops of the block and having an even spacing around the centre thereof.

The ends of the filament18 are attached to certain ones of the wires 23 as will be obvious, one of these latter wires being extended to make contact with the plug member 10, as indicated at 23. The other wires 23 form, as will be apparent, a series of taps or branches engaging the filament at different points along its length so that when current is directed through different ones of these wires a greater or lesser length of. the filament will be caused to glow.

For thus directing the current, the usual centre contact of these incandescent lamps is in the form of a rod 27 which is surrounded by a suitable insulating filling and is extended at its inner end into the chambers 12 and has rotatably mounted thereon a double-armed contact bar 28 having an operating handle 29 projecting through a suitable arcuate slot 30 in the plug part 11. The two arms of the contact bar 28 have contacts 31 thereon adapted to engage, one at a time, the contacts 24.. The two arms of the bar 28 are arranged at an angle to one another,this angle being preferably equal to one-half the angular spacing of the contacts 24, so that the contacts carried by the respective arms of the bar 28 alternately engage the contacts 24 on opposite sides of v vided to make an air tight joint. The bulb may be held in place by screws 37 passing through registering openings therein and in the flanges 14 and 14'. To enable the air to be exhausted from the bulb we mount on the flange 13 a small hand operated suction pump 38 of any ordinary construction.

As will be apparent, with our improved incandescent lamp the filament can be readily replaced in case of damage While a wide variation of the amount of light furnished can be obtained.

-,IlaVing thus described -our invention which we claim as new and desire 'to protect by Letters Patent of the United States is as follows:

In an electric incandescent lamp, a plug element presenting a switch chamber therein, an insulating block inserted in said element and forming the bottom wall of said chamber, a series of wires carried by an angle to one ;another equal to one-half the angular spacing of the said contacts.

In testimonywhereof we have afiixed our signatures.

JOSEPH ARDO. FRANK MELFO. 

